• 한국잠사곤충학회지
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• 제42권1호
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• pp.48-57
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• 2000

This study was undertaken to figure out the effects of hydrolysis conditions on the solubility of insoluble sericin, molecular weight distribution and thermal characteristics of hydrolysates in enzymatic hydrolysis by Alcalase 2.5L. It was indicated that the optimum treatment temperature and pH for the insoluble sericin were 50$\^{C}$ and 11, respectively. When the insoluble sericin was hydrolyzed with a various treatment conditions, the solubility of all hydrolysates were represented above 85% at given conditions. As the enzyme concentration increased, the solubility increased roughly, but the solubility increasement ratio was less above 2% enzyme concentration. As the treatment time increased, the solubility was also increased. It was showed in the molecular weight distribution of hydrolysates treated various enzyme concentrations and treatment times that when enzyme concentrations were 0.5, 2, 3%, the peaks of the distribution curve were shifted to left side which meant low molecular weight and was distributed much quantity with shifted to be left side, but treatment time was 6 hr. the peak was shifted to right side. When enzyme concentration was 5% and treatment time was below 2 hr., the peaks were shifted to right side, but treatment time was above 4hr. the peak was shifted to left side. The number-average molecular weights were distributed from 300 to 800 and those were decreased when treatment time was up to 4 hr., but increased a little when treatment time was 6hr. It was showed in the DSC curves of hydrolysates treated with treatment time of 0.5, 1, 2, 4, 6 hr. fixed 1% o.w.s enzyme concentration and control that the endothermic peak was observed near at 200$\^{C}$. The denaturation peak of the hydrolysates depending on treatment times had a tendency to shift to higher temperature. But, when the treatment time was 6 hr., the peak was shifted to lower temperature comparing another hydrolysates.

• KSBB Journal
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• 제10권5호
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• pp.540-546
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• 1995

bacterial alkaline protease를 이 용한 corn glu ten meal의 효소가수분해시 pH, 온도, 효소대 기질의 질량비율 등에 따른 반응특성 및 반응의 적정화 를 꾀하였고, 효소의 deactivation여부에 초점을 맞추어 효소반응속도론적 방정식을 제안조사하였다. 그 결과,$50^{\circ}C$, pH 9~10에서 가장 높은 가수분해 도를 나타내었고 $e_0/s_o$가 높을수록 반응속도 빛 최종 가수분해도가 증가하였다. 최종가수분해도는 gluten meal전체질량기준으로 17~20%, gluten meal내의 단백질질량기준으로 25 ~ 28 % 였다. 반응후반에서의 반응속도감소의 주된 원인은 기 질소진 (substrate de pletion) 이며 이때 enzyme deactivation 및 product inhibition의 영향은 미미한 것으로 확인되었다. 효소 deactivation항을 무시하여 변형시킨 model equa-tlOn에 의해 이 효소반응에 해당하는 여러 kinetic parameter들의 값을 계산분석한 결과 product inhi bition효과가 미미함을 확인하였다. 변형된 kinetic equation과 실험적으로 얻은 가수분해 데이타는 거 의 완벽하게 일치하였다. 효소반응을 $100\times$scale­u up한 결과 가수분해 profile 및 가수분해도는 $1\times$ 와 비교시 거의 일치하였으므로 이 효소반응이 용이하 게 scale-up될 수 있음을 확인하였고, 아미노산분석 결과 가수분해액을 미생물발효기질용 질소원으로 사 용할 수 있음을 제시하였다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.504-507
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• 2000

Enzymatic hydrolysis of cellulose was studied with emphasis on the effect of cellulase loading and pulp sludge concentration on glucose yield. Enzyme loading appeared to have a significant effect on glucose yield. Chemical pretreatment had no effect on enzymatic hydrolysis of pulp sludge. High glucose yield was obtained from enzymatic hydrolysis, especially at sludge concentrations lower than twenty percent. The optimum concentrations of crude cellulase and ${\beta}-glucosidase$ were 5 U/mL and 8 U/mL, respectively, considering the amount of enzymes used and glucose produced.

• 한국식품영양학회지
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• 제8권2호
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• pp.79-87
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• 1995

It is generally known that the protein of talk has allergenicity and the allerenicity Induces allergic diseases. Finding methods to reduce the allergenicity of the food and develop methods to make low allergic food is the purpose of this study. For this study, 1 tried various experimental methods : heat treatment, irradation with ultraviolet and microwaves treatment with polyphosphate, enzyme hydrolysis and PCA inhibition test using guinea pigs and degrees of hydrolysis. The results obtained are as follows. Heat treatment reduced allergenicity of milk protein. The higher the heat, the better the effect. Irradiating with ultraviolet and microwave increased both the degree of protein hydrolysis and PCA inhibition reduced the allergenicity. Ultraviolet was more effective than microwaves on milk protein. Enzyme treatment increased the degree of hydrolysis and PCA inhibition, and reduced allergenicity considerably. Neutrase was more effective than alcalase on milk protein. Adding Polyphosphate did not induced protein hydrolysis, but increased PCA inhibition and reduced allergenicity.

• Food Science and Biotechnology
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• 제16권3호
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• pp.482-484
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• 2007

To investigate production and hydrolysis of levan, the levansucrase enzymes from Zymomonas mobilis ATCC 10988 and Rahnella aquatilis ATCC 33071 were used. The optimum temperature of R. aquatilis levansucrase for levan formation was $37^{\circ}C$, whereas that of Z. mobilis was $4^{\circ}C$, under the experimental conditions. Both levansucrases also catalyzed the reverse levan hydrolysis reaction. Levan hydrolysis reactions from both levansucrases were temperature dependent; high temperature ($20^{\circ}C$) was more favorable than low temperature ($4^{\circ}C$) by 4 times. Fructose was the only product from hydrolysis reaction by both levansucrases, showing that both levansucrases mediated the hydrolysis reaction of exo-enzyme acting. In both enzymes, initial levan hydrolysis activity was almost accounted to 1% of initial levan formation activity. The results allow the estimation of the fructose release rate in enzyme processing conditions.

• 한국식품과학회지
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• 제50권2호
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• pp.203-208
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• 2018

본 연구에서는 항염증 펩타이드를 생산하기 위해 도루묵(Arctoscopus japonicus)의 어육과 알로부터 가수분해물을 제조하였으며, 단백분해효소, pH, 온도, 효소 농도 및 가수분해 시간에 따른 NO 소거활성을 측정함으로써 최적 가수분해 조건을 설정하였다. 어육 가수분해물의 최적 조건은 pH 5.0, 온도 $30^{\circ}C$, 효소 농도 1%, 가수분해 시간 4시간으로 확인되었으며, 알 가수분해물의 최적 조건은 pH 5.0, 온도 $70^{\circ}C$, 효소 농도 3%, 가수분해 시간 3시간으로 확인되었다. 이러한 최적의 가수분해 조건에서 어육 및 알 가수분해물의 NO 소거활성은 각각 18.94 및 19.81%로 측정되었다. 이는 도루묵 단백질 가수분해물 유래 항염증 펩타이드를 생산하기 위한 기초자료로 활용할 수 있을 것으로 기대된다.

• 생명과학회지
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• 제17권9호통권89호
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• pp.1260-1265
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• 2007

자석으로 분리가 가능한 ${\alpha}-Amylase$가 코팅된 나노고분자를 제조하여 녹말의 분해공정에 활용하였다. 본 연구에서 개발된 고정화 효소의 안정성은 크게 증가하여 상온에서 200rpm으로 교반하면서 보관한 경우 30일 동안에 92.7%의 활성도를 유지하였다 . 고정화 효소를 자석을 이용하여 재사용한 경우 10 회 동안 사용했을 경우 95.2%의 활성도 회수율을 보 여 효소의 재사용 가능성을 확인시켜 주었다 . 고정화 효소 0.5mg을 사용하여 녹말 분해 공정 에 활용하였을 때 2 ml의 40 g/l 녹말 용액을 40분만에 완전히 분해 시켰다, 이러한 고정화 효소를 사용하여 연속 효소반응기를 개발하여 녹말 분해공정에 활용한 결과 체류시간을 1시간으로 하였을 때 녹말 30 g/l를 76% 분해시켜 산업적으로 활용 가능성을 보여 주었다.

• Journal of Ginseng Research
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• 제40권2호
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• pp.105-112
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• 2016

Background: Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms. Methods: Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at $25^{\circ}C$ for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30-80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1. Results: Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}$ compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72-96 h, pH 4.0-4.5, and temperature $45-55^{\circ}C$. Conclusion: AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.407-413
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• 1996

A novel type of extracellular phospholipase $A_1$ was isolated from Serratia sp. MK1 and purified to homogeneity by ammonium sulfate precipitation, anion exchange and gel filtration chromatography. The purified enzyme was a monomer with a molecular mass of about 43, 000 Da. This enzyme showed the highest lipolytic activity toward phosphatidylserine among the phosphoglycerides tested, and preferentially catalyzed the hydrolysis of the ester bond in phosphatidic acid to lyso-phosphatidic acid. Enzyme activity was completely inhibited by the addition of a chelating agent such as EDTA, and inhibited enzyme activity was fully recovered by the presence of $Ca^{2+}$. This implies that the enzyme requires $Ca^{2+}$ for activity. The enzyme was stable up to $70^{\circ}C$ when incubated for 1 h at pH 8.5, and the optimal pH and temperature were 8.5 and $50^{\circ}C$, respectively.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.525.2-525
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• 1986

Cephalexin synthesizing enzyme (${\alpha}$ amino acid ester hydrolase) was partially purified from the culture broth of Acetobacter turbidans ATCC9325 through ammonium sulfate fractionation, DEAE, CM, and Sephacryl S-200 gel filtration. The enzyme has optimum pH 6.0 and temperature, 40$^{\circ}C$ respectively. From the analysis of reaction mixtures by thin layer chromatographic and high performance liquid chromatographic techniques, it was confirmed this enzyme catalyzed simultaneously the following reactions : 1) Synthesis of cephalexin from D-${\alpha}$-phenylglycine methylester (PGM) and 7-amino 3-deacetoxy-cetoxycephalosporanic acid (7-ADCA) 2) Hydrolysis of cephalexin to form 7-ADCA and phenylglycine (PG) 3) Hydrolysis of PGM to form PG and methanol. Base on the above experimental observations, the reaction model of this enzyme was identical with that of the enzyme from Xanthomonas citri.